1 #ifndef _LINUX_VIRTIO_BLK_H 2 #define _LINUX_VIRTIO_BLK_H 3 /* This header is BSD licensed so anyone can use the definitions to implement 4 * compatible drivers/servers. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. Neither the name of IBM nor the names of its contributors 15 * may be used to endorse or promote products derived from this software 16 * without specific prior written permission. 17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. */ 28 #include "standard-headers/linux/types.h" 29 #include "standard-headers/linux/virtio_ids.h" 30 #include "standard-headers/linux/virtio_config.h" 31 #include "standard-headers/linux/virtio_types.h" 32 33 /* Feature bits */ 34 #define VIRTIO_BLK_F_SIZE_MAX 1 /* Indicates maximum segment size */ 35 #define VIRTIO_BLK_F_SEG_MAX 2 /* Indicates maximum # of segments */ 36 #define VIRTIO_BLK_F_GEOMETRY 4 /* Legacy geometry available */ 37 #define VIRTIO_BLK_F_RO 5 /* Disk is read-only */ 38 #define VIRTIO_BLK_F_BLK_SIZE 6 /* Block size of disk is available*/ 39 #define VIRTIO_BLK_F_TOPOLOGY 10 /* Topology information is available */ 40 #define VIRTIO_BLK_F_MQ 12 /* support more than one vq */ 41 #define VIRTIO_BLK_F_DISCARD 13 /* DISCARD is supported */ 42 #define VIRTIO_BLK_F_WRITE_ZEROES 14 /* WRITE ZEROES is supported */ 43 #define VIRTIO_BLK_F_SECURE_ERASE 16 /* Secure Erase is supported */ 44 45 /* Legacy feature bits */ 46 #ifndef VIRTIO_BLK_NO_LEGACY 47 #define VIRTIO_BLK_F_BARRIER 0 /* Does host support barriers? */ 48 #define VIRTIO_BLK_F_SCSI 7 /* Supports scsi command passthru */ 49 #define VIRTIO_BLK_F_FLUSH 9 /* Flush command supported */ 50 #define VIRTIO_BLK_F_CONFIG_WCE 11 /* Writeback mode available in config */ 51 /* Old (deprecated) name for VIRTIO_BLK_F_FLUSH. */ 52 #define VIRTIO_BLK_F_WCE VIRTIO_BLK_F_FLUSH 53 #endif /* !VIRTIO_BLK_NO_LEGACY */ 54 55 #define VIRTIO_BLK_ID_BYTES 20 /* ID string length */ 56 57 struct virtio_blk_config { 58 /* The capacity (in 512-byte sectors). */ 59 __virtio64 capacity; 60 /* The maximum segment size (if VIRTIO_BLK_F_SIZE_MAX) */ 61 __virtio32 size_max; 62 /* The maximum number of segments (if VIRTIO_BLK_F_SEG_MAX) */ 63 __virtio32 seg_max; 64 /* geometry of the device (if VIRTIO_BLK_F_GEOMETRY) */ 65 struct virtio_blk_geometry { 66 __virtio16 cylinders; 67 uint8_t heads; 68 uint8_t sectors; 69 } geometry; 70 71 /* block size of device (if VIRTIO_BLK_F_BLK_SIZE) */ 72 __virtio32 blk_size; 73 74 /* the next 4 entries are guarded by VIRTIO_BLK_F_TOPOLOGY */ 75 /* exponent for physical block per logical block. */ 76 uint8_t physical_block_exp; 77 /* alignment offset in logical blocks. */ 78 uint8_t alignment_offset; 79 /* minimum I/O size without performance penalty in logical blocks. */ 80 __virtio16 min_io_size; 81 /* optimal sustained I/O size in logical blocks. */ 82 __virtio32 opt_io_size; 83 84 /* writeback mode (if VIRTIO_BLK_F_CONFIG_WCE) */ 85 uint8_t wce; 86 uint8_t unused; 87 88 /* number of vqs, only available when VIRTIO_BLK_F_MQ is set */ 89 __virtio16 num_queues; 90 91 /* the next 3 entries are guarded by VIRTIO_BLK_F_DISCARD */ 92 /* 93 * The maximum discard sectors (in 512-byte sectors) for 94 * one segment. 95 */ 96 __virtio32 max_discard_sectors; 97 /* 98 * The maximum number of discard segments in a 99 * discard command. 100 */ 101 __virtio32 max_discard_seg; 102 /* Discard commands must be aligned to this number of sectors. */ 103 __virtio32 discard_sector_alignment; 104 105 /* the next 3 entries are guarded by VIRTIO_BLK_F_WRITE_ZEROES */ 106 /* 107 * The maximum number of write zeroes sectors (in 512-byte sectors) in 108 * one segment. 109 */ 110 __virtio32 max_write_zeroes_sectors; 111 /* 112 * The maximum number of segments in a write zeroes 113 * command. 114 */ 115 __virtio32 max_write_zeroes_seg; 116 /* 117 * Set if a VIRTIO_BLK_T_WRITE_ZEROES request may result in the 118 * deallocation of one or more of the sectors. 119 */ 120 uint8_t write_zeroes_may_unmap; 121 122 uint8_t unused1[3]; 123 124 /* the next 3 entries are guarded by VIRTIO_BLK_F_SECURE_ERASE */ 125 /* 126 * The maximum secure erase sectors (in 512-byte sectors) for 127 * one segment. 128 */ 129 __virtio32 max_secure_erase_sectors; 130 /* 131 * The maximum number of secure erase segments in a 132 * secure erase command. 133 */ 134 __virtio32 max_secure_erase_seg; 135 /* Secure erase commands must be aligned to this number of sectors. */ 136 __virtio32 secure_erase_sector_alignment; 137 138 } QEMU_PACKED; 139 140 /* 141 * Command types 142 * 143 * Usage is a bit tricky as some bits are used as flags and some are not. 144 * 145 * Rules: 146 * VIRTIO_BLK_T_OUT may be combined with VIRTIO_BLK_T_SCSI_CMD or 147 * VIRTIO_BLK_T_BARRIER. VIRTIO_BLK_T_FLUSH is a command of its own 148 * and may not be combined with any of the other flags. 149 */ 150 151 /* These two define direction. */ 152 #define VIRTIO_BLK_T_IN 0 153 #define VIRTIO_BLK_T_OUT 1 154 155 #ifndef VIRTIO_BLK_NO_LEGACY 156 /* This bit says it's a scsi command, not an actual read or write. */ 157 #define VIRTIO_BLK_T_SCSI_CMD 2 158 #endif /* VIRTIO_BLK_NO_LEGACY */ 159 160 /* Cache flush command */ 161 #define VIRTIO_BLK_T_FLUSH 4 162 163 /* Get device ID command */ 164 #define VIRTIO_BLK_T_GET_ID 8 165 166 /* Discard command */ 167 #define VIRTIO_BLK_T_DISCARD 11 168 169 /* Write zeroes command */ 170 #define VIRTIO_BLK_T_WRITE_ZEROES 13 171 172 /* Secure erase command */ 173 #define VIRTIO_BLK_T_SECURE_ERASE 14 174 175 #ifndef VIRTIO_BLK_NO_LEGACY 176 /* Barrier before this op. */ 177 #define VIRTIO_BLK_T_BARRIER 0x80000000 178 #endif /* !VIRTIO_BLK_NO_LEGACY */ 179 180 /* 181 * This comes first in the read scatter-gather list. 182 * For legacy virtio, if VIRTIO_F_ANY_LAYOUT is not negotiated, 183 * this is the first element of the read scatter-gather list. 184 */ 185 struct virtio_blk_outhdr { 186 /* VIRTIO_BLK_T* */ 187 __virtio32 type; 188 /* io priority. */ 189 __virtio32 ioprio; 190 /* Sector (ie. 512 byte offset) */ 191 __virtio64 sector; 192 }; 193 194 /* Unmap this range (only valid for write zeroes command) */ 195 #define VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP 0x00000001 196 197 /* Discard/write zeroes range for each request. */ 198 struct virtio_blk_discard_write_zeroes { 199 /* discard/write zeroes start sector */ 200 uint64_t sector; 201 /* number of discard/write zeroes sectors */ 202 uint32_t num_sectors; 203 /* flags for this range */ 204 uint32_t flags; 205 }; 206 207 #ifndef VIRTIO_BLK_NO_LEGACY 208 struct virtio_scsi_inhdr { 209 __virtio32 errors; 210 __virtio32 data_len; 211 __virtio32 sense_len; 212 __virtio32 residual; 213 }; 214 #endif /* !VIRTIO_BLK_NO_LEGACY */ 215 216 /* And this is the final byte of the write scatter-gather list. */ 217 #define VIRTIO_BLK_S_OK 0 218 #define VIRTIO_BLK_S_IOERR 1 219 #define VIRTIO_BLK_S_UNSUPP 2 220 #endif /* _LINUX_VIRTIO_BLK_H */ 221